U.S. Pat. No. 3,997,239 discloses a portable microscope that is assembled from shell-shaped parts. The microscope stage is mounted on an arm, and can be displaced in the direction of the optical axis of the microscope via an eccentric cam. An artificial illumination system for the specimens on the microscope stage is not provided.
U.S. Pat. No. 4,361,377 also describes a portable and compact microscope that is equipped on the housing with a plurality of adjustment elements. The specimen to be examined is introduced through a slot in the housing. Illumination occurs via at least one conventional incandescent bulb that can be connected to a battery to supply power.
U.S. Pat. No. 5,062,697 discloses a portable microscope that is assembled from two cylindrical components. An illumination device and an energy source by means of a battery are housed in one cylindrical component. The microscope serves principally for the examination of blood samples. A switch, with which the power supply for illumination is switched on or off, projects out from the cylindrical wall.
European Patent Application EP-A-0 528 100 discloses a portable microscope that has a cylindrical shape. An opening in the housing into which a specimen slide can be inserted is opened up by means of a slider. A circuit is also closed thereby, so that the lamp provided for illumination is supplied with power.